NORTH OLMSTED, Ohio (AP) — A 3-year-old boy was fatally stabbed by a woman as he sat in a grocery cart in a supermarket parking lot. Investigators said Tuesday that they believe it was a random attack.

The boy’s mother also was stabbed, but her injuries were not life-threatening, said Sgt. Matt Beck, a detective with North Olmsted police.

Officers arrested 32-year-old Bionca Ellis, of Cleveland, while she was walking away from the scene with a knife in her hand on Monday, police said. She was being held on a charge of aggravated murder.

Ellis was inside the Giant Eagle grocery when she saw the boy and his mother near the front of the store and then followed them into the parking lot in North Olmsted, a Cleveland suburb, Beck said.

The boy’s mother was about to load her groceries into her vehicle when Ellis ran at them with a knife, stabbing both of them, police said. The boy later died at a hospital.

The county medical examiner identified the boy as 3-year-old Julian Wood. His mother, Margot Wood, was treated at a hospital, police said. Investigators said Ellis had no known previous interactions with the mother and her son.

Calls to a listing for Ellis went unanswered Tuesday. It was not clear whether she has an attorney.